Centrifugally engaged coil clutch with weight lock

ABSTRACT

The centrifugally actuated spring clutch illustrated includes two pairs of alternately positioned centrifugal weight members, one pair of which, under the action of centrifugal force, frictionally engages an energizing cup attached to a coil-wound torque spring for effecting the driving of an output shaft. The second pair of weight members abuts respective adjacent actuating weight members to supplement the force thereof and to thus serve as torque-multipliers therefor, enabling heavy torque loads to be driven by a relatively compact clutch assembly. A lock plate may be manually moved to lock both pairs of weights in an inoperative position.

United States Patent 91 Briar 1 Apr. 17, 1973 1 1 CENTRIFUGALLY ENGAGEDCOIL FOREIGN PATENTS OR APPLICATIONS CLUTCH WITH WEIGHT LOCK 787 2309/1935 France 192/101 B [75] Inventor: John R. Briar, Dayton, Ohio aPrimary Examiner-Benjamin W. Wyche [73] Asslgnee' 3:1 :32 r CorporationArlorney-W'arren E. Finken et a1.

[22] Filed: Feb. 9, 1972 [57] ABSTRACT I 21 1 Appl. No.: 224,769 Thecentrifugally actuated spring clutch illustrated ineludes two pairs ofalternately positioned centrifugal 'weight members, one pair of which,under the action 1 2 Cl "192/105 25; 3,3 of centrifugal force,frictionally engages an energizing l l cup attached to a coil-woundtorque spring for effect- I i the driving of an output shaft. The secondp of Fleld of Search B, i members abuts respective adjacent actuating192/35 114 81 77 weight members to supplement the force thereof and tothus serve as torque-multipliers therefor, enabling [56] References cuedheavy torque loads to be driven bya relatively com- UNITED STATESPATENTS pact clutch assembly.v A lock plate may be manually moved tolock both pairs of weights in an inoperative 1,204,392 11/1916 Bartmess..l92/105 CE position, 1,826,054 10/1931 Chryst ....l92/l05 CE 2,360,12410/1944 Greenlee [92/195 CD 6 Claims, 2 Drawing Figures a f Q f 2; Y l2334 fiz /11!; //2

l5 k 63 T s 1/ e e \reaw W 4 A5" /a M w "I 97L: 1; 47/

.... w W .9 m

1w x I} 41 57/22 l :z 11/ l q ift 374 will -iz I 4? v 7 7 CENTRIFUGALLYENGAGED COIL CLUTCH WITH WEIGHT LOCK This invention relates generally toclutches and, more particularly, to centrifugally actuated springclutches for use with automotive air compressors.

When air-conditioning is employed on a vehicle, it is preferred that thecompressor not be a load on the engine starter at engine start-up, butrather that the compressor be actuated automatically at a predeterminedrpm to drive a predetermined load. It is also desirable that thecentrifugal clutch used for such an application be as compact aspossible.

Accordingly, a general object of the invention is to provide improvedcompact centrifugal weight means for engaging and expanding a coil-woundtorque spring to interconnect a drive pulley and an output shaft oncethe engine reaches a predetermined rpm during engine start-up, and tobecome disengaged at a predetermined lower rpm.

Another object of the invention is to provide an improved centrifugalclutch including a compact centrifugal weight cluster which is adaptableto a relatively small clutch housing and assembly, while being suitablefor efficiently driving substantially heavy torque loads.

A further object of the invention is to provide an improvedcentrifugally actuated spring clutch including actuating weight membersand additional cooperating torque-multiplier weight members.

These and other objects and advantages of the invention will becomeapparent when reference is made to the following description andaccompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a centrifugal clutch embodying theinvention, taken along the plane of line ll of FIG. 2, and looking inthe direction of the arrows; and 1 FIG. 2 is a cross-sectional viewtaken along-the plane of line 2-2 of FIG. 1, as if FIG. 1 were afull-round view, and looking in the direction of the arrows.

Referring now to the drawings in greater detail, FIG. 1 illustratesa'centrifugal clutch assembly including a cast iron cylindrical housing12 having a pulley groove 14 formed therein. A drive belt 16 is mountedin the groove 14. The housing 12 is mounted on bearings 18 which, inturn, are mounted around a fixed sleeve member 20, which may extend froman air-conditioning compressor 21. A first shoulder 22 and a firstgroove 24 are formed adjacent opposite ends of the inner periphealsurface 26 of the housing 12, while a second shoulder 28 and a secondgroove 30 are formed on the outer peripheral surface 32 of the sleevemember 20. A snap ring 34 is mounted in the groove 24, and a retainerring 36 is mounted in the groove 30, the shoulders 22 and 28 and therings 34 and 36 serving to retain the housing l2 and the sleeve memberin axial alignment with one another on the bearings 18. The sleevemember 20 is mounted on needle bearings 38 around a compressor shaft 40which extends through the center of the centrifugal clutch 10 to thecompressor 21.

A cylindrical extension 42 is formed on the housing 12 and has acounterbored surface 44 formed therein. A steel back-up plate member 46is mounted in a recess 48 formed in the bottom of the counterboredsurface 44 and is secured thereinby a plurality of screws (not shown)threadedly mounted in suitable threaded openings formed in the housing12. A pair ofoppositely disposed pivot pins 50 and 52 (FIG. 2) aresecured to the plate member 46. A I

An additonal plate member 54 (FIG. 1) is mounted around the shaft 40adjacent the back-up plate member 46. A lever arm 56 is secured by anysuitable means to the plate member 54 and extends radially outwardlytherefrom through a circumferentially slotted opening 58 formed 1n thecylindrical extension 42 of the pulley housing 12. Arcuate slots 60 areformed in the plate member 54 to accommodate the extension therethroughof the two pivot pins 50 and 52. A pair of oppositely disposed pins 61and 62 are secured to the plate member 54, as illustrated in FIG. 2. Acontoured retainer clip 64, secured to the pulley housing 12 by bolts65, serves to retain the lever arm 56 either in the upper or lower (FIG.2) portions of the slotted opening 58, depending upon the operativeposition selected.

A pair of weight members 66 and 68 are pivotally mounted adjacent theplate member 54 on the pivot pins 50 and 52, respectively, and retainedthereon by retaining rings 70 mounted in grooves 72 formed adjacent theends of the-pivot pins 50 and 52. A spacer or bearing washer 74 ismounted on each pivot pin 50 and 52 intermediate the respectiveretaining rings 70 and the adjacent faces of the weight members 66 and68. Each of the weight members 66 and 68 includes a shoe 76 of asuitable friction material bonded or secured in any other suitablemanner to the outermost arcuateshaped surface 78 thereof.

A notch-like groove or cam surface 80 is formed adjacent an end portionof an arcuate-shaped extension portion 82 of each weight member 66 and68. A pin 84 is mounted on each extension portion 82 adjacent eachgroove 80. Spring or wire members 86 and 88 are each secured at one endthereof to each pin 84 and secured at the other ends thereof torespective oppositely disposed pins 90 and 92 fixed on the plate member46.

A straight end portion 94 formed on each wire member 86 and 88 ismounted in'a slot 96 formed in each pin 90 and 92. The central portionof each spring is curved or otherwise shaped so as to permit portion 82to pivot outwardly from pin 92.

A second pair of generally arcuate-shaped weight members 98 and 100 aresecured to the pins 90 and 92, respectively, intermediate the adjacentweight members 66 and 68. A notched portion 101 is formed in each weightmember 98 and 100 to avoid contact with the pins 61 and 62 on the platemember 54. It may be noted in FIG. 2 that surfaces 102 and 103 on theweight members 98/100 and 82, respectively, are substantially in contactwith one another.

A coil-wound torque spring 104 is mounted within the counterboredsurface 44 of the cylindrical extension 42 of the pulley housing 12,with the inner end face 106 thereof secured to an outwardly extendingflange 107 formed on an annular wall or energizing cup 108 mountedaround the weight members 66,68, 98,

and 100. The flange 107 is positioned slightly apart The cover member111 includes an outer cylindrical wall portion 113 which surrounds andis operatively connected to an outer extended end tab 114 of thecoilwound torque spring 104 and is rotatable therewith. The cover member111 also includes a hub portion 116 which is secured to an end portion118 of the compressor shaft 40 by means of a key 120. The hub portion 116 is retained in place on the shaft-end portion 1 18 by a washer 122, aretainer ring 124 and a nut 126 threadedly mounted on the threaded end128 of the compressor shaft 40, the retainer ring 124 being mounted in'agroove 130 formed in the hub portion 116 to axially position the torquespring 104 relative to the pulley housing 12 and the shaft 40.

A seat member 132 is mounted in a recess 134 formed in the inner end ofthe sleeve member 20. A retainer ring 136, mounted in an annular groove138 formed on the inner peripheral surface of the sleeve member 20,retains the seat member 132 fixed in position against a shoulder 140formed on the inner surface of the sleeve member 20. An O-ring seal 142is mounted in an annular groove 144 also formed in the inner peripheralsurface of the sleeve member 20 adjacent the outer surface of the fixedseat member 132. A carbon ring 146 is mounted around the compressorshaft 40 with its end face 148 slidably mounted against the adjacentface 150 of the fixed seat member 132. An O-ring seal 152 abuts againsta shoulder 154 formed on the inner surface of the carbon ring 146 toprevent leakage around the compressor shaft 40. A compressed spring 156abuts against a retainer member 158 which is secured against a shoulder160 formed on the compressor shaft 40, and urges the O-ring seal 152against the shoulder 154, retaining the carbon ring 146 in contact withthe face 150 of the fixed seat member 132. An axially extending finger162 extends from the retainer member 158, to the right in FIG. 1,adjacent a projection 164 formed on the carbon ring 146 to effectuatethe rotation of the carbon ring 146 with the shaft 40.

' OPERATION Referring now to FIG. 2, it may be noted that if the leverarm 56 were positioned in its uppermost or socalled winter position inthe slotted opening 58, and

retained there by the retainer clip 64, the pins 61 and 62 would bepositioned in the notches or cam surfaces 80 adjacent the ends of theextension portions 82 of the weight members 66 and 68, respectively,thus serving to retain the weight members 66 and 68 in their radiallyinnermost positions. This is the so-called winter" or nonrunning"position when it is desirable that the compressor 21 be inoperative. inthis position the weight members 66 and 68 are prevented from respondingto the action of centrifugal force and, hence, the compressor shaft 40will remain stationary. The weight members 98 and 100 are also preventedfrom responding to the action of centrifugal force by virtue of thecontact between adjacent surfaces 102 and 103 of the members 98/100 and82, respectively, while the members 82 are retained by the pins 61 and62.

When'it is desired to have the compressor 21 become operative, i.e.,once warm weather arrives, the lever arm 56 is moved into the lowermostor summer" position in the slotted opening 58, as illustrated in FIG. 2.Since the pivot pins and 52 are secured to the fixed back-up plate 46,the arcuate slots 60 formed in the plate member 54 permit the plate 54to be rotated relative thereto without interference from the pivot pins50 and 52. It may be noted that the pins 61 and 62, which are secured tothe plate member 54, are thus rotated in a clockwise direction out ofthe respective cam 'surfaces or notches and extension portions 82 as aresult of the movement of the lever arm 56. This permits the weightmembers 66 and 68 to be pivoted outwardly under the action ofcentrifugal force about the pivot pins 50 and 52, against the force ofthe respective spring members 86 and 88.

Once the weight members 66 and 68 have pivoted outwardly under theaction of centrifugal force of a predetermined engine speed of, say, 300rpm, the shoes 76 will frictionally engage the energizing cup 108. Sincethe latter is engaged at its end 'fiange 107 to the inner end face 106of the coil-wound torque spring 104, the torque spring 104 will beforced outwardly into contact with the inner surface 44 of the pulleyhousing 12. This causes the torque spring 104, as well as the covermember 111, which is contacted by the end tab 114 of the spring 104, tobegin to rotate along with the pulley housing 12. Inasmuch as the covermember 111 includes the hub portion 116 and the latter, in turn, iskeyed to the compressor shaft 40 by the key 120, rotation of the covermember 111 will rotate the compressor shaft 40 accordingly and thusactuate the compressor 21. Full driving engagement will have beenattained at approximately engine idle, say, 600 rpm.

To accommodate substantially large compressor 21 torque loads, withoutresorting to a larger centrifugal clutch arrangement, the engaging forceof the shoes 76' against the energizing cup 108 as a result of theaction of centrifugal force on the weight members 66 and 68 issupplemented by the outward movement of the weight members 98 and underthe action of centrifugal force, as a result of the contact between theadjacent surfaces 102 and 103 of the adjacent respective weight members98/100 and extension 82.

Once the engine speed has reduced to a predetermined level, say, 50 rpm,the springs 86 and 88 will return the extensions 82 inwardly, thusreturning the respective weight members 66/98 and 68/100 to theirnondriving positions.

It should be apparent that the invention provides improved compactcentrifugal clutch means for efficiently driving substantially heavytorque loads at a predetermined engine operating speed and to disengagesame at a predetermined lower engine speed.

While but one embodiment of the invention has been shown and described,other modifications thereof are possible.

lclaim:

1. A centrifugal clutch arrangement comprising a cylindrical housing, apulley groove formed on the outer periphery of said cylindrical housing,an output shaft, bearing means for rotatably mounting said cylindricalhousing at one end thereof on said output shaft, a coil-wound torquespring loosely mounted withinthe inner periphery of the other end ofsaid cylindrical housing, connector means secured between the outer endof said torque spring and said output shaft, 21 first pair of oppositelydisposed weight members pivotally connected to said cylindrical housingradially within said coilcwound torque spring for causing the expansionof said coil-wound torque spring into contact with said cylindricalhousing to be driven thereby, and a second pair of oppositely disposedweight members positioned alternately with said first pair of weightmembers for respectively abutting against said first pair of weightmembers to supplement the engaging force thereof' 2. A centrifugalclutch arrangement comprising a cylindrical housing, a pulley grooveformed on the outer periphery of said cylindrical housing, an outputshaft, bearing means for rotatably mounting said cylindrical housing onsaid output shaft, a recess formed in one end of said cylindricalhousing, a coil-wound torque spring mounted within the inner peripheryof said recess with a narrow clearance therebetween while said torquespring remains in an unstressed condition, connector means securedbetween the outer end of said torque spring and said output shaft, afirst pair of oppositely disposed weight members pivotally mounted onthe bottom surface of said recess radially within said coil-wound torquespring, an annular wall member mounted intermediate said first pair ofweight members and said torque spring and connected to the inner end ofsaid torque spring, said first pair of weight members contacting saidannular wall member under the action of centrifugal force to cause saidturque spring to expand to engage the adjacent wall of said recess, anda second pair of oppositely disposed weight members positionedalternately with said first pair of weight members for respectivelyabutting against said first pair of weight members to supplement theengaging force thereof.

3. The centrifugal clutch arrangement described in claim 2, and manuallyactuated means operatively mounted in said cylindrical housing forrendering said weight members inoperative under the action ofcentrifugal force.

4. The centrifugal clutch arrangement described in claim 3, and a camsuface formed adjacent the free end of each of said first pair of weightmembers, and wherein said manually actuated means includes a platemember rotatably mounted intermediate said bearing means and the ajacentfaces of said weight members, a pair of oppositely disposed pin members'formed on said plate member, and lever means on said plate member formanually rotating said plate member to move said pin members intocontact with said respective cam surfaces on said first pair of weightmembers, thereby rendering said first and second pairs of weight membersinoperative under the action of centrifugal force.

5. A centrifugal clutch arrangement comprising a cylindrical housing, apulley groove formed on the outer periphery of said cylindrical housing,an output shaft, bearing means for rotatably mounting said cylindricalhousing on said output shaft, a counterbore formed in one end of saidcylindrical housing, a coilwound torque spring mounted within the innerperiphery of said counterbore, an annular wall member mounted within theinner periphery of said coil-wound torque spring and secured to the.innermost end thereof, a cover member secured between the outermost endof said torque sprlng and an end portion of said output shaft, first andsecond pairs of oppositely disposed pivot pins fixed on the bottomsurface of said counterbore, first and second pairs of weight memberscircumferentially aligned and pivotally mounted on said respective firstand second pairs of pivot pins'radially within said annular wall member,a friction shoe mounted on the radially outer surface of each of saidfirst pair of weight members, a first contacting surface formed on eachof said first pair of weight members adjacent the respective free endsthereof, a second contacting surface formed on each of said second pairof weight members adjacent the respective pivotal ends thereof, saidfriction shoes contacting said annular wall member under the action ofcentrifugal force on said first pair of weight members and causing saidtorque spring to expand and engage said inner periphery of saidcylindrical housing at a predetermined engaging force, thereby drivingsaid output shaft via said cover member, said predetermined engagingforce being supplemented by the pressure of said second contactingsurfaces of said second pair of weight members against said firstcontacting surfaces of said first pair of weight members under theaction of centrifugal force, and spring means connected between saidfree ends of said first pair of weight members and said second pair offixed pivot pins for returning said first and second pairs of weightmembers to their rspectiveradially inner nondriving positions oncecentrifugal force has subsided to a predetermined level.

6. The centrifugal clutch arrangement described in claim 5, and a camsurface formed on the radially outer surface of each of said first pairof weight members adjacent the free ends thereof, a plate memberrotatably mounted intermediate said bottom surface of said counterboreand the adjacent faces of said weight members, a pair of arcuate slotsformed in said plate member for mounting around each of said first andsecond pairs of oppositely disposed pivot pins, a pair of oppositelydisposed fixed pin members formed on said plate member, lever means onsaid plate member for manually rotating said plate member to move saidfixed pin members into contact with said respective cam surfaces,thereby rendering all of said weight members inoperative under theaction of centrifugal force, and retainer clip for retaining said platemember in position once manually rotated.

I i III

1. A centrifugal clutch arrangement comprising a cylindrical housing, apulley groove formed on the outer periphery of said cylindrical housing,an output shaft, bearing means for rotatably mounting said cylindricalhousing at one end thereof on said output shaft, a coil-wound torquespring loosely mounted within the inner periphery of the other end ofsaid cylindrical housing, connector means secured between the outer endof said torque spring and said output shaft, a first pair of oppositelydisposed weight members pivotally connected to said cylindrical housingradially within said coil-wound torque spring for causing the expansionof said coil-wound torque spring into contact with said cylindricalhousing to be driven thereby, and a second pair of oppositely disposedweight members positioned alternately with said first pair of weightmembers for respectively abutting against said first pair of weightmembers to supplement the engaging force thereof.
 2. A centrifugalclutch arrangement comprising a cylindrical housing, a pulley grooveformed on the outer periphery of said cylindrical housing, an outputshaft, bearing means for rotatably mounting said cylindrical housing onsaid output shaft, a recess formed in one end of said cylindricalhousing, a coil-wound torque spring mounted within the inner peripheryof said recess with a narrow clearance therebetween while said torquespring remains in an unstressed condition, connector means securedbetween the outer end of said torque spring and said output shaft, afirst pair of oppositely disposed weight members pivotally mounted onthe bottom surface of said recess radially within said coil-wound torquespring, an annular wall member mounted intermediate said first pair ofweight members and said torque spring and connected to the inner end ofsaid torque spring, said first pair of weight members contacting saidannular wall member under the action of centrifugal force to cause saidtorque spring to expand to engage the adjacent wall of said recess, anda second pair of oppositely disposed weight members positionedalternately with said first pair of weight members for respectivelyabutting against said first pair of weight members to supplement theengaging force thereof.
 3. The centrifugal clutch arrangement describedin claim 2, and manually actuated means operatively mounted in saidcylindrical housing for rendering said weight members inoperative underthe action of centrifugal force.
 4. The centrifugal clutch arrangementdescribed in claim 3, and a cam suface formed adjacent the free end ofeach of said first pair of weight members, and wherein said manuallyactuated means includes a plate member rotatably mounted intermediatesaid bearing means and the ajacent faces of said weight members, a pairof oppositely disposed pin members formed on said plate member, andlever means on said plate member for manually rotating said plate memberto move said pin members into contact with said respective cam surfaceson said first pair of weight members, thereby rendering said first andsecond pairs of weight members inoperative under the action ofcentrifugal force.
 5. A centrifugal clutch arrangement comprising acylindrical housing, a pulley groove formed on the outer periphery ofsaid cylindrical housing, an output shaft, bearing means for rotatablymounting said cylindrical housing on said output shaft, a counterboreformed in one end of said cylindrical housing, a coil-wound torquespring mounted within the inner periphery of said counterbore, anannular wall member mounted within the inner periphery of saidcoil-wound torque spring and secured to the innermost end thereof, acover member secured between the outermost end of said torque spr1ng andan end portion of said output shaft, first and second pairs ofoppositely disposed pivot pins fixed on the bottom surface of saidcounterbore, first and second pairs of weight members circumferentiallyaligned and pivotally mounted on said respective first and second pairsof pivot pins radially within said annular wall member, a friction shoemounted on the radially outer surface of each of said first pair ofweight members, a first contacting surface formed on each of said firstpair of weight members adjacent the respective free ends thereof, asecond contacting surface formed on each of said second pair of weightmembers adjacent the respective pivotal ends thereof, said frictionshoes contacting said annular wall member under the action ofcentrifugal force on said first pair of weight members and causing saidtorque spring to expand and engage said inner periphery of saidcylindrical housing at a predetermined engaging force, thereby drivingsaid output shaft via said cover member, said predetermined engagingforce being supplemented by the pressure of said second contactingsurfaces of said second pair of weight members against said firstcontacting surfaces of said first pair of weight members under theaction of centrifugal force, and spring means connected between saidfree ends of said first pair of weight members and said second pair offixed pivot pins for returning said first and second pairs of weightmembers to their respective radially inner nondriving positions oncecentrifugal force has subsided to a predetermined level.
 6. Thecentrifugal clutch arrangement described in claim 5, and a cam surfaceformed on the radially outer surface of each of said first pair ofweight members adjacent the free ends thereof, a plate member rotatablymounted intermediate said bottom surface of said counterbore and theadjacent faces of said weight members, a pair of arcuate slots formed insaid plate member for mounting around each of said first and secondpairs of oppositely disposed pivot pins, a pair of oppositely disposedfixed pin members formed on said plate member, lever means on said platemember for manually rotating said plate member to move said fixed pinmembers into contact with said respective cam surfaces, therebyrendering all of said weight members inoperative under the action ofcentrifugal force, and retainer clip for retaining said plate member inposition once manually rOtated.